81432567 has 64 divisors (see below), whose sum is σ = 135475200. Its totient is φ = 48107520.

The previous prime is 81432553. The next prime is 81432577. The reversal of 81432567 is 76523418.

It is not a de Polignac number, because 81432567 - 2⁶ = 81432503 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81432517) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 839463 + ... + 839559.

It is an arithmetic number, because the mean of its divisors is an integer number (2116800).

Almost surely, 2^81432567 is an apocalyptic number.

81432567 is a deficient number, since it is larger than the sum of its proper divisors (54042633).

81432567 is a wasteful number, since it uses less digits than its factorization.

81432567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213 (or 207 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 81432567 is about 9023.9995013298. Note that the first 3 decimals coincide. The cubic root of 81432567 is about 433.4437134328.

The spelling of 81432567 in words is "eighty-one million, four hundred thirty-two thousand, five hundred sixty-seven".